The present invention relates to improvements in the performance and durability of watercraft such as boats, ships, tankers, etc. through the use of hull sheaths, foam layer buoyancy, water filled open cylinder stabilizing of crafts, and moveable pontoon adjustments to buoyancy and stability. No art was located that disclosed double sheath hull covering configurations.
Maklezow, in US application 20040149197, describes an integrated, compartmentalized, water impermeable hull that is constructed of a plurality of lengthwise tubes sandwiched between two support layers. The tubes are parallel and in contact, each with at least one other. They are not intended to be filled with water nor open to the ambient water.
Many unsinkable structures are provided with inflatables for temporary remediation until rescue or repair can be effected. Examples include U.S. Pat. Nos. 6,758,158, 6,550,415, 6,431,108, and 6,408,782. Wenstob et al. in U.S. Pat. No. 4,919,067 uses a combination of rigid and reversibly inflatable pontoons for both unsinkability and self-righting. The system is permanent and reusable.
Jones, et al., in U.S. Pat. No. 4,541,356 describes a multihull vessel capsize prevention device including first and second tubes disposed longitudinally along the lower portion of the keel of the vessel through which seawater flows during the sailing of the vessel. Each of the tubes includes forward and rearward watertight valves. The mass of the water within the tubes serves to prevent capsize about one of the outriggers of the vessel. These cylinders are used for a multihull craft and not in conjunction with other stabilizing means such as pontoons or sealed foam layers. Further they are not adjacent the hull but attached at a distance below the multihull craft.
Seidel in U.S. Pat. No. 6,327,988 describes a watercraft with multiple buoyancy chambers in the deck of the craft. Under normal operation each chamber is filled with air. In case of a breach or other high risk situation, chambers then are filled with a closed cell foam to counteract any loss in buoyancy. Hence the foam is used only during periods of emergency and is dependent on the foam producing mechanism working in a timely fashion during an emergency in order to be effective.
Berg, et al., in US application 20020092453 describe a rolling multiple cover assembly for a barge. The use of multiple covers prevents damage to the cargo should one of the covers become damaged. The covers are to insure protection of the barge cargo and do not provide protection to the barge itself per se neither above nor below the water.
Hill, et al. in US application 20030084834 describes an apparatus for protecting a hull of a watercraft that includes a waterproof shroud of flexible sheet material suspended from a collar which is floatable. This single shroud appears to be intended to provide a protective enclosure during mooring and not during use of the craft.
Rice in U.S. Pat. No. 6,755,142 and US application 20030121463 describes a modular pontoon system made of air filled modules combined to form a single pontoon. There is no suggestion to fill the modules with foam.
Trepanier in US applications 20040079270 and 20040040488 describes a pontoon shell filled with multiple segments of filler that can be closed cell foam. It may also include a ballast section. No details are given as to methods of usage nor of attachment to watercraft.
None of the background art describes a moving hull sheath system. Neither does the art use sealed foam layers below the deck and/or cylinders open to the water attached to monohull craft. Hence there is considerable need for a method of rapid damage repair along with means for increased stability and ‘unsinkability’.